1. Field of the Invention
This invention relates to a device for blocking of an optical lens and a method for blocking of an optical lens.
2. Description of Related Art
An optical lens, for example, for eyeglasses, should have certain optical properties. The associated desired optical data of the lens are determined for example, by an optician. These data comprise for example, the specification of the diopters, data on sphere and cylinder, on the pantoscopic angle, etc. Furthermore, these desired optical data can also contain the distance and/or the location to an assigned eye, especially with installation into a certain eyeglass frame, therefore, for example, the pantoscopic angle, facial shape angle and the lens tilt angle, pupil distance, etc.
In the past, lenses with predetermined optical data, for example, with diopters which were available in different stages, were used. However, increasingly lenses which have the individualized optical data desired at the time and the associated optical properties are being used. These lenses are then machined or produced depending on the respectively desired optical data, the lenses being machined especially by cutting, preferably by turning and/or milling. For this purpose the lenses are clamped, their being first blocked, as explained below.
German Patent Application DE 10 2008 022 660 A1 discloses a method for machining of a lens, the lens to be worked being temporarily fastened (blocked) on a so-called block piece as a holder. The lens is joined to the block piece, especially by means of a block material, during the blocking. Then, the block piece is ejected by means of a centrally acting ejector. The block piece can then be clamped in order to work the lens.
This invention relates to the blocking of a lens. “Blocking” is defined as the temporary joining of the lens to the assigned block piece, especially by means of a block material. The block piece therefore especially forms a holder, preferably for later machining of the lens.
International Patent Application Publication WO 2011/054665 A1 relates to deblocking—therefore the release—of the block material from a lens. This invention conversely relates to the release of the block from the device for blocking. However, in the case of the present invention, releasing of the lens or a lens blank from the block material should not take place; rather the block composed of the lens or lens blank, block material and block piece will remain altogether joined in the device according to the invention and the method according to the invention.